Fredholmness and invertibility of Toeplitz operators with matrix almost periodic symbols

Rodman, Leiba; Spitkovsky, Ilya; Woerdeman, Hugo

doi:10.1090/S0002-9939-01-06276-1

Fredholmness and invertibility of Toeplitz operators with matrix almost periodic symbols
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by Leiba Rodman, Ilya M. Spitkovsky and Hugo J. Woerdeman PDF

Proc. Amer. Math. Soc. 130 (2002), 1365-1370 Request permission

Abstract:

We consider Toeplitz operators with symbols that are almost periodic matrix functions of several variables. It is shown that under certain conditions on the group generated by the Fourier support of the symbol, a Toeplitz operator is Fredholm if and only if it is invertible.

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